In recent years, a fuel cell has received attention as a power source of a mobile phone, a laptop personal computer, etc. Since hydrogen is used as fuel of its fuel cell, a container for storing the hydrogen is required and a hydrogen filling apparatus for filling its container with the hydrogen is required. Also, it is sufficiently considered that a general household is used as a use place of the hydrogen filling apparatus with the widespread use of the fuel cell.
In this case, it is necessary that a general consumer can make safe and simple use in the household. Concretely, avoidance of a risk such as ignition by handling hydrogen, establishment of a proper cooling method of the case of a hydrogen storage container made of a hydrogen absorbing alloy, ensuring of simple operability capable of being handled even by the general consumer, etc. are required.
Several proposals have already been made in a method for filling a container with hydrogen.
For example, in Patent Literature 1, a filling pressure and a temperature of a hydrogen storage container are detected in detection of the amount of filling and based on T-P-C characteristics of a hydrogen absorbing alloy, the remaining amount of hydrogen is measured and a hydrogen filling ratio is obtained. Also, as cooling and risk prevention measures, the hydrogen storage container is placed in a low-temperature chamber and this low-temperature chamber may be a water bath, an ice bath and any low-temperature chamber as long as a temperature lower than ordinary temperature can be maintained.
In Patent Literature 2, detection of the amount of filling is detected by a filling pressure and a temperature of a hydrogen storage container and a hydrogen supply amount is controlled by a valve so as to fill up based on PCT characteristics of a hydrogen absorbing alloy. Also, as cooling and risk prevention measures, the hydrogen storage container is cooled by a low-temperature bath using a refrigerant.
In Patent Literature 3, a method in which hydrogen is generated using a polyelectrolyte water electrolysis device and a fill-up is detected by detecting a hydrogen pressure in detection of the amount of filling and filling of hydrogen is once stopped at a point in time when a filling pressure of hydrogen reaches a certain degree of value and a hydrogen filling ratio is decided by a decrease rate of the hydrogen pressure of the subsequent supply buffer tank and refilling is performed when necessary is adopted. Also, as cooling and risk prevention measures, cooling is performed using a cooling part into which a tubular evaporator and a refrigerator dedicated to cooling are incorporated and also as leakage hydrogen measures, hydrogen is induced using a dedicated fan etc. and combustion processing is performed by a leakage hydrogen processing part.
In Patent Literature 4, an apparatus for filling a hydrogen storage container with hydrogen generated from a water electrolysis device is proposed. This apparatus is constructed so as to fill directly while suppressing variations in pressure of the water electrolysis device by disposing a buffer tank or a flow rate regulating valve between the water electrolysis device and a filling device.
Patent Literature 1: JP-A-6-103987
Patent Literature 2: JP-A-8-128597
Patent Literature 3: JP-A-2002-269633
Patent Literature 4: JP-A-2003-119586